Electric heater



J. C. SHARP ELECTRIC HEATER Jan. 21 1941.

Filed Jan. 28, 1938 Inventor:

John C.Shar-p, M

L H i '5 At tovney.

Patented Jan. 21, 1941 UNITED STATES snnc'rmc minim John C. Sharp, Oak Park, 111., assignor to Edison General Electric Appliance Company, Ghicago, 11L, a corporation of New York Application January 28, 1938, Serial No. 187,416 1 Claims. (01. 219 -37) This invention relates to electric heaters, and it has for its object the provision of an'improved device of this character, and one which is compact and rugged in its construction, and reliable and efllcient in its operation.

This invention relates more specifically to electric heating devices of the hot-plate type such as are commonly used on electric ranges and which support the articles being heated by direct contact. And this invention further contemplates the provision in a device of this charactor of an improved construction whereby the heating element may be easily and quickly removed from the range and whereby its parts are readily accessible for cleaning when it is removed.

In accordance with this invention, suitable reilector members are provided below the heating element of the unit which are separable from each other, and also from the unit. The reflector 20 members when in their proper operative positions under the heating element form a'substantially continuous reflecting surface. The reflector members are further arranged to be supported in their normal operative positions when the heating unit is inserted in its opening in the range by engagement with the supporting flange which usually is provided on the range top around the heating unit openings. The heating unit is further provided with supporting means for the reflectors attached to the heating element and spaced below the reflectors so as to perform no function when the heating unit is in its normal operative position. However, when the heating unit is elevated from the range top opening, it moves the support to engage and hold the reflectors. It is further arranged so that the reflectors can be quickly and easily removed from the support for the purpose of cleaning.

This invention further contemplates improved connector structure for securing supply leads to the terminals of the heater.

For a more complete understanding of this invention, reference should be had to the accompanying drawing in which Fig. 1 is an. elevation mainly in section of an electric range hot-plate arranged in accordance with this invention; Fig. 2 is an elevation taken at right angles to Fig. .l and showing parts in section so as to illustrate certain details of construction; Fig. 3 is a plan view of the heating element in its position shown in Fig. 2, parts being broken away so as to illusheating unit intended to be used as the hot-plate of an electric range. The heating unit, comprises a pair of heatingelement's l and H arranged in spiral form and nested one within the other, as shown in Fig. 3. I prefer to use heating elements of the sheathed type, such as described and claimed in the United States patent to Charles C. Abbott No. 1,367,341, dated February 1, 1921. Briefly, these heating units comprisea helical resistance conductor I! mounted in a metallic sheath I3 and supported in spaced relation with reference to the sheath bya layer H of electrically insulating and heat conducting material, such as powdered magnesium oxide. The units are supported by means of a framework [5 having roughly the shape of a cross. As shown, the framework I 5 comprises a straight transverse portion l5a and two arms l5b extending laterally therefrom. The

upper edges of the sections I511. and 8522 are provided with spaced notches l6 which receive the heating elements. The heating elements are secured by the upper edges of these notches which flare outwardly toward each other, as clearly shown in Fig. i. The supporting framework It in turn is supported in a ring member ll which has a circular upright flange iii to which the end sections of the arms l5 and 850. are directly secured. For this purpose, the flange is provided with vertical slits 19 through which projections or reduced sections 20 on the ends of the arms are inserted. To facilitate the assembly of the support IS with the flange elongated horizontal slits 2| are provided in the flange at the bottom of the vertical slits IS. The sections 22 of the flange below the slits 2! 'may then be forced outwardly so as to permit the ends 2c of the support to move freely upwardly into the vertical slits it, after which the sections 22 are forced inwardly to their positions shown more clearly in Figs. 1 and 3, to securely lock the frame to the ring, The ring ll further comprises a flat annular ring surface 23 and this terminates in a downwardly extending circular flange 24. V

,The ring I! with the heating unit mounted on it is arranged to be inserted in an opening 25 in the range top 26. The range top 2c is provided with a seat defined by an intumed flange 28 and the outer flange 24 of the ring H is adapted to be mounted in the seat 28 to support the heating unit within the opening 25. When thus mounted, the annular surface 23 is substantially flush with the range top 26. The support I5 is mounted in the ring II so that the upper surfaces of the heating elements l0 and II project above the plane of the ring surface 23 whereby utensils and the like may be placed in direct thermal control with the heating elements.

- The terminal ends Mia and Ila. of the heating elements I! and I I extend downwardly at right angles to the plane of the heating elements through the ring flange It, as shown in Fig. 2. Terminals 29a secured to the ends of the resist ance conductors I2 project from these terminal ends of the heating elements, as shown in Fig. 4,

and, are received in an insulating block 281) constituting a terminal housing, as will be pointed out in greater detail hereinafter.

A pair of semi-circular reflector members 29 are adapted to be positioned under the heating elements I and II, as shown in Fig. 1. Each reflector member has a bottom wall 30 which is of semi-circular form, as shown in Fig. 3. At

the outer arc-shaped edge of this surface 39 is an upright semi-circular flange'3l which at its upper edge terminates in an annular ring-shaped flange 32. This flange 32 is arranged to rest on the seat 28 of the range top to support the reflector member in its proper normal operative position shown in the drawing. A The two reflector members 29 in these portions cooperate to form a shallow pan under the heating element which pan not only functions as a reflector, but also functions to collect overflow from the cooking utensils, such as water, edibles and the like. Preferably, the bottom wall 30 of each reflector will taper downwardly from the center to the outer edges, as shown, and at these outer edges gaging and holding the .reflector members 29 when the heating unit is elevated from the range opening 25 so as to prevent them from falling away from the unit. This supporting means comprises an elongated member 35 which has roughly an elongated oval shape having lower and upper arms 36 and 31 Joined at the center by an upright arm 39. The two lower arms 35 of this member are rigidly secured to the insulating block 28b by means of a bolt 39. The two upper arms 31 are spaced somewhat below the reflector members 29, as shown, and these arms are arranged to support the reflector members when the unit is elevated from its opening. At the center of the unit where the two chord edges of the reflectors meet, the arms 31 and the upright 38 are provided with a notched section 49. The notch 43 is arranged to receive down-turned flanges 4| provided along the chord edges of the reflectors. Thus, when the heating element is elevated, the support 35 secured to it also is raised so that the two upper arms 31 eventually engage the under surface of the bottoms 39 of the reflectors. Under this condition, the down-turned flanges 4| are received in the notch 49 to secure the reflectorsto the support 35. The reflectors, therefore; will be carried upby inserting them into their proper positions and dropping the flanges 4| into the notch 49. They will be carried on the support 35 until their other flanges 32 rest on the seat 29. It will be observed that the drain openings 33 are so positioned that drippage flowing through them cannot engage and defile the support 35.

The support 35 is stabilized by means of an arm 4la which is rigidly secured to the downturned terminal section Ila. of the heating ele-' ment I I, as shown.

Each terminal end of the heater is provided with a cup-shaped terminal housing 42 which has a tapered neck section 43 inserted in the outer end of the metallic sheath I3 of the heater, which preferably also will be tapered, as shown. The housing 42 is secured to the sheath by means of a bushing 44 which surrounds the terminals 28a of the heater element. These terminals are received in apertures 45 provided for them in the terminal housing 28b; and the terminal housing on its upper surface is provided with protuberances 41 around these openings. These protuberances cooperate with the cups 42 to prevent the entrance of moisture, dirt, grease and the like into the terminals.

The terminal housing is formed into mating sections 43 and 49, the upper section 48 of which, as shown, bears against the outer edges of the terminal cups 42. The upper housing is provided with a series of chambers 50 to which a series of elongated channels 5| are connected. The channels 5| accommodate the electrical supply leads 52, and the chambers 59 receive suitable connector members 53 which function to connect.

shown. Arranged within the loop 55 is nut 53a which when the screw is turned inwardly to clamp the terminal is threaded outwardly against the opposite arm of the loop. The lead 52, as shown, is secured between the nut and this opposite loop, the parts being so arranged that the lead is securely clamped when the screw is turned inwardly to clamp the terminals 281).

It will be observed that the two inner termi nals Illa and Ha of the two heater elements are electrically connected together by a conducting strip 51 which lies within a channel 5.3 within the member 43. The chambers 59 and channels 5| and 53 are closed by the lower section 49 of the terminal housing which is secured to the upper. section by the bolts 39.

If desired, a grounding lead 59 may be provided in a channel 5|, and secured to the screw 39.

While I have shown a particular embodiment of my invention, it will be understood, 01' course,. that I do not wish to be limited thereto sincemany modifications may be made. and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric range heating unit adapted to be inserted in the opening of a range top that has a supporting surface for the unit adjacent the opening comprising a ring adapted to rest on said surface, a heating element'secured to said ring, a plurality of separable reflector members below said heating element cooperating to form a reflecting surface below the heating element, said reflector members having curved flanges adapted to rest on said supporting surface to hold said members in their operative positions under said heating element, a second support spaced below said heating element comprising a plurality of arms attached to said heating element andextending outwardly under said reflecting members respectively sothat when said ring is elevated A bers, said second support having a notch arranged to receive flanges on said reflector members to prevent them from falling away from said arms when said ring is elevated, and the distance between said second support and said heating element providing for movement of said reflector members upwardly from said notch so that they can be removedlaterally from said heating element and ring.

2. An electric heater comprising a heating element, a support on which said heating element rests, a plurality of reflectors resting on said support so as to form a heat reflecting surface below said heating element, a second support hav ing a plurality of arms for said reflectors spaced below them and rigidly attached to said heating element, said second support having a notched section and said reflectors having parts arranged first support.

3. An electric heating unit adapted to be inserted in the opening of an electric range top that has a supporting surface comprising a supporting ring adapted to be placed on said supporting surface, a heating element mounted in said ring, a pair of substantially semi-circular reflectors below said heating element constructed and arranged so that their outer edges rest on said supporting surface to hold the reflectors in position under the heating element to form a circular reflecting surface, a support spaced below said heating element and ring attached to said heating element and having a notched section substantially at the center of said circular reflecting surface and a pair of supporting arms directed away in opposite directions from said notched section and inclined downwardly from .said section, and said reflectors having downturned flanges at their chords arranged to be received in said notched section to hold said reflectors to said heating element when said ring is elevated from said supporting surface, the supporting arms being spaced a suflicient distance below said heating element to provide for removal of said reflectors laterally by lifting their flanges from said notched section and laterally withdrawing them in the space between said arms and said heating element and ring.

4. An electric heating unit adapted to be supported in the opening of an electric range top plate that has a supporting seat for said unit comprising a heating element adapted to rest on said seat, a pair of reflectors of semi-circular shape cooperating the deflne a reflecting surface below said heating element and having flanges at their outer edges adapted to rest on said seat,

and also having down-turned flanges at their chords, a support below said reflectors in spaced relation with them, connecting means extending between said support and said heating'element rigidly securing them together, and said support having a notch arranged to receive said downturned flanges to hold said reflectors when said heating element is elevated from said seat, and

' also having supporting arms for said reflectors.

5. An electric heating unit adapted to be supported on a seat provided for it below the opening of an electric range top plate comprising a ring having an outer edge adapted to rest on said seat, and at its inner edge having a flange, a heating element secured to said flange having terminal portions turned downwardly through said ring, a terminal block secured to the terminal ends below said heating element and ring, a pair of semicircular reflectors between said heating element and ring and said terminal block and having flanges at their outer edges adapted to rest on said seat, and down-turned flanges at their chords, and a support secured to said terminal block spaced from the reflectors and having a notch arranged to receive said down-turned flanges to hold said reflectors when said ring and heating element are elevated from said seat, and also having a plurality of supporting arms, one for each of said reflectors.

6. An electric heater comprising a supporting ring, a heating element secured to said ring, a pair of reflectors below said heating element cooperating to form a circular reflecting surface and each having as its outer arc-shaped edge an upright flange so that the two reflectors form a pan-shaped container below said heating element, and each reflector tapering downwardly toward its flange and having drain openings near said flange, and also an outwardly extending flange at the top of said upright flange, a common flxed support for said outwardly extending flanges of said reflectors and said ring, and a second support secured to said heating element spaced from the bottom of said reflectors having supporting arms for engaging and supportingthem when the heating element and ring are elevated from said flxed support.

7. A range heating unit adapted to be in- 1 serted in the opening'of a range top that is provided with a supporting surface for said heat: ing unit comprising a heating element adapted to be mounted on said surface, heat-reflecting members separate from said heating element and adapted to be supported by said surface beneath said heating element in a normally operative position so as to constitute a reflectin surface under said heating element which also functions as a bottom wall to collect overflow from said heating element, a normally inoperative support below said'reflecting members, means extending between said heating element and sup-- port rigidly securing them together so that when said heating element is elevated from said opening said support is carried upwardly with it and when so moved engages and carries said reflecting members upwardly out of said opening so that they may be separated and withdrawn, and said reflecting members having drain openings for said overflow located so that the discharge falling through them does not contact said port. H= I l JOHN C. SHARP. 

